Elon Musk made some rather wild promises at the International Astronautical Congress last week: his SpaceX company is going to start sending people to Mars by 2024, and in 40 to 100 years, he will have a million of us living there.

I have one big question about this. Why bother? Mars is a rotten place to live. You can’t breathe, eat, drink or go outdoors; the soil’s toxic, constant radiation streams in from space, and the average temperature is -60C. It looks rather bleak to me, but for some people I suppose the clincher would be that messages home would take 15 minutes, and “it would be hard to Skype with anybody”, according to Ashwin Vasavada of Nasa’s Mars Science Laboratory.

But Musk is determined to plough on, make us a “multi-planet species” and turn Mars into “a really nice place to be”. I try to keep calm, but this is where I blow a gasket. We already have somewhere “really nice” to be. I gaze around my garden at the sunflowers, grapes, twittering birds, luscious greenery and general loveliness and can’t help but wonder why anyone would want to go and live on a freezing, poisonous, giant boulder prone to overwhelming dust storms that might well cock-up the machinery on which their life depends.

There is being adventurous and curious, and then there is being overambitious, verging on potty. Lovely that Musk produces electric cars, warns us of the dangers of AI and a killer-robots arms race, and is sending life-saving battery packs to Puerto Rico, but why diddle about planning a fantasy colonisation on Mars for when this planet goes down the pan?

I know we have a throwaway culture, but why chuck a whole planet because it’s a bit worn out and go searching for another one to cack-up? Why not get rid of all our plastic, Musk, if you’re so clever, and mend what we’ve got? Why obsess over SpaceX?

“What I love about SpaceX,” says Prof Alan Duffy, of Swinburne University of Technology, Melbourne, “is that they make things profitable at every step of the way.” That must be my answer. D’oh.